Fix issue incremental upload can evict textures being drawn

cc/prioritized_texture.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 
 #include "CCPrioritizedTexture.h"
 
 #include "CCPrioritizedTextureManager.h"
 #include "CCPriorityCalculator.h"
@@ skipping 111 matching lines @@
 {
     setDimensions(IntSize(), GraphicsContext3D::RGBA);
     setIsSelfManaged(true);
     m_bytes = bytes;
 }
 
 CCPrioritizedTexture::Backing::Backing(unsigned id, CCResourceProvider* resourceProvider, IntSize size, GC3Denum format)
     : CCTexture(id, size, format)
     , m_owner(0)
     , m_priorityAtLastPriorityUpdate(CCPriorityCalculator::lowestPriority())
-    , m_ownerExistedAtLastPriorityUpdate(false)
     , m_wasAbovePriorityCutoffAtLastPriorityUpdate(false)
+    , m_inDrawingImplTree(false)
     , m_resourceHasBeenDeleted(false)
 #ifndef NDEBUG
     , m_resourceProvider(resourceProvider)
 #endif
 {
 }
 
 CCPrioritizedTexture::Backing::~Backing()
 {
     ASSERT(!m_owner);
@@ skipping 12 matching lines @@
     setId(0);
     m_resourceHasBeenDeleted = true;
 }
 
 bool CCPrioritizedTexture::Backing::resourceHasBeenDeleted() const
 {
     ASSERT(CCProxy::isImplThread());
     return m_resourceHasBeenDeleted;
 }
 
+bool CCPrioritizedTexture::Backing::canBeRecycled() const
+{
+    ASSERT(CCProxy::isImplThread() && CCProxy::isMainThreadBlocked());
+    return !m_wasAbovePriorityCutoffAtLastPriorityUpdate && !m_inDrawingImplTree;
+}
+
 void CCPrioritizedTexture::Backing::updatePriority()
 {
     ASSERT(CCProxy::isImplThread() && CCProxy::isMainThreadBlocked());
     if (m_owner) {
-        m_ownerExistedAtLastPriorityUpdate = true;
         m_priorityAtLastPriorityUpdate = m_owner->requestPriority();
         m_wasAbovePriorityCutoffAtLastPriorityUpdate = m_owner->isAbovePriorityCutoff();
     } else {
-        m_ownerExistedAtLastPriorityUpdate = false;
         m_priorityAtLastPriorityUpdate = CCPriorityCalculator::lowestPriority();
         m_wasAbovePriorityCutoffAtLastPriorityUpdate = false;
     }
 }
 
+void CCPrioritizedTexture::Backing::updateInDrawingImplTree()
+{
+    ASSERT(CCProxy::isImplThread() && CCProxy::isMainThreadBlocked());
+    m_inDrawingImplTree = !!owner();
+    if (!m_inDrawingImplTree)
+        ASSERT(m_priorityAtLastPriorityUpdate == CCPriorityCalculator::lowestPriority());
+}
+
 } // namespace cc